Microwave Preparation of SiO2-B2O3-Na2O-K2O-CaO-Fe2O3-TiO2 Glass System

Abstract

This study reports preparation of glass composition (54.50 wt.%) SiO2, (10.80 wt.%) B2O3, (14.20 wt.%) Na2O, (1.20 wt.%) K2O, (6.00 wt.%) CaO, (4.00 wt.%) Fe2O3 and (9.30 wt.%) TiO2 by melt quenching method using direct microwave heating and conventional resistive heating. Study of dielectric loss factor of the glass as function of temperature illustrated increasing loss factor above 370 o C, 550 o C, 650 o C and 900 o C, indicating enhanced microwave absorption by the glass at above these temperatures. Chemical analysis results of both the glasses depicted more volatilization loss of volatile ingredients in conventional heating. The study of chemical durability was performed from leachate analysis describing less leaching of Na2O, K2O and other constituents from glass melted in microwave furnace. Glass transition temperatures (Tg) were found to be 576.3 o C and 569.5 o C for glass melted in conventional and microwave heating route, respectively. Laboratory experiment of glass melting utilizing microwave energy as an alternate heating source demonstrated 70%-75% electrical power saving.